Difference between revisions of "Magic cancellation"

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'''Magic cancellation''', or, shortly, '''MC''', is a property of some pieces of [[armor]] which protects against a wide variety of special melee attacks by monsters, such as [[poisonous]] [[killer bee]] stings and [[lycanthropy]] through [[werejackal]] bites. Generally, magic cancellation protects against magical attacks where the monster touches the player with some part of its body. Each piece of armor has a magic cancellation number ranging from 0 to 3, where 0 is the lowest (worst) and 3 is the highest (best). Note that magic cancellation is ''not'' cumulative ― your magic cancellation is the maximum of that provided by any single piece of your armour. Having the highest magic cancellation means that only 1/50 of magical, body-to-body melee attacks will succeed (assuming they would hit otherwise). Note that not all special attacks are considered magical, see the list below for details.
+
{{For|the effects of a [[wand of cancellation]] or a [[spell of cancellation]]|cancellation}}
 +
'''Magic cancellation''', or '''MC''' for short, is a graduated property in ''[[NetHack]]'' which protects the [[player]] character from certain non-damaging effects caused by a monster using a contact-making attack.
  
−
==Tables==
+
==Description==
 +
Magic cancellation offers a certain amount of protection against "special melee attacks" made against a character - examples include [[poison]] from [[killer bee]] stings, [[lycanthropy]] caused by [[werejackal]] bites, and the [[green slime]]'s [[sliming]] attacks. Having the highest (best) grade of magic cancellation means that only {{frac|10}} of special melee attacks will succeed (assuming they would hit otherwise). This makes magic cancellation a high priority trait. A precise list of the special melee attacks that magic cancellation protects against is provided in the [[#How it works|section below]].
 +
 
 +
Magic cancellation must not be confused with [[cancellation]] caused by a wand or spell, nor with [[magic resistance]]. See {{sa|Differences from cancellation and magic resistance|sectionsign=true}} for further details.
 +
 
 +
Your current level of magic cancellation can be verified via any source of [[enlightenment]]; "You are warded" means you have MC1, "You are guarded" is MC2, and "You are protected" is MC3.
 +
 
 +
==Sources==
 +
The most common source of magic cancellation is [[armor]]. Each piece of armor has a magic cancellation number (MC number) ranging from 0 (worst) to 3 (best). Note that magic cancellation from armor is ''not'' cumulative—the player's magic cancellation is the maximum of that provided by any single piece of armor worn. This means that if you are wearing a [[chain mail]] with MC 1, ''and'' a [[dwarvish cloak]] with MC 1, then your magic cancellation is still 1.
 +
 
 +
Magic cancellation can also be granted by [[protection]], either [[intrinsic]] or [[extrinsic]].  Extrinsic protection augments your magic cancellation by 1, to a maximum of 3.  Intrinsic protection or temporary protection from the [[spell of protection]] counts as magic cancellation 1, but doesn't stack with armor sources or extrinsic protection.  The sources of extrinsic protection are the [[ring of protection]], the [[Tsurugi of Muramasa]], and the [[Mitre of Holiness]]; more than one such source provides no additional benefit.  Intrinsic protection is granted when you get an [[AC]] bonus by donating to an [[aligned priest]] or by a [[favor]] when [[pray]]ing.  Intrinsic protection may be lost by a [[gremlin]]'s special attack or eating a [[disenchanter]] corpse; if so, donating the appropriate amount to an aligned priest will restore it, even if it would fail to improve your AC.  [[High priest]]s have extrinsic protection, and [[aligned priest]]s and monsters represented by {{monsym|Angel}} have intrinsic protection.
 +
 
 +
The following list contains all the sources of magic cancellation:
  
−
The relationship between magic cancellation level and chance of a body-to-body magical attack success is as follows:
 
 
{|class="wikitable"
 
{|class="wikitable"
−
! Magic cancellation number
+
!Armor
−
! Chance of attack succeeding
+
!Armor type
 +
!MC
 +
|-
 +
|Extrinsic protection
 +
|style="text-align:center" rowspan="3" |N/A
 +
|style="text-align:center" rowspan="1" |+1 (max 3)
 +
|-
 +
|Intrinsic protection
 +
|style="text-align:center" rowspan="2" |1 (if no extrinsic)
 +
|-
 +
|[[spell of protection]]
 +
|-
 +
|[[alchemy smock]]
 +
|style="text-align:center" rowspan="9" |[[cloak]]
 +
|style="text-align:center" rowspan="20" |1
 +
|-
 
|-
 
|-
−
|Magic Cancellation 0 ||  <math>\frac{150}{150}</math>, i.e. 100%
+
|[[cloak of displacement]]
 
|-
 
|-
−
|Magic Cancellation 1 ||  <math>\frac{101}{150}</math>, i.e. ~67%
 
 
|-
 
|-
−
|Magic Cancellation 2 || <math>\frac{52}{150}</math>, i.e. ~35%
+
|[[cloak of invisibility]]
 +
|-
 +
|-
 +
|[[cloak of magic resistance]]
 +
|-
 +
|-
 +
|[[dwarvish cloak]]
 +
|-
 +
|-
 +
|[[elven cloak]]
 +
|-
 +
|-
 +
|[[leather cloak]]
 +
|-
 +
|-
 +
|[[mummy wrapping]]
 +
|-
 +
|-
 +
|[[orcish cloak]]
 +
|-
 +
|-
 +
|[[banded mail]]
 +
|style="text-align:center" rowspan="10" |[[body armor]]
 +
|-
 +
|[[bronze plate mail]]
 +
|-
 +
|-
 +
|[[chain mail]]
 +
|-
 +
|-
 +
|[[leather armor]]
 +
|-
 +
|-
 +
|[[orcish chain mail]]
 +
|-
 +
|-
 +
|[[orcish ring mail]]
 
|-
 
|-
−
|Magic Cancellation 3 ||  <math>\frac{3}{150}</math>, i.e. 2%
 
−
|}
 
−
 
−
All [[cloak]]s, some pieces of [[body armor]] and the [[cornuthaum]] provide non-zero magic cancellation. The following pieces of armor are the only ones with non-zero magic cancellation:
 
−
{|class="wikitable"
 
−
! Armor name
 
−
! Armor type
 
−
! Magic cancellation number
 
 
|-
 
|-
−
|[[alchemy smock]] || [[cloak]] || 1
+
|[[ring mail]]
 
|-
 
|-
−
|[[chain mail]] || [[body armor]] || 1
 
 
|-
 
|-
−
|[[mummy wrapping]] || [[cloak]] || 1
+
|[[scale mail]]
 
|-
 
|-
−
|[[orcish chain mail]] || [[body armor]] || 1
 
 
|-
 
|-
−
|[[orcish ring mail]] || [[body armor]] || 1
+
|[[splint mail]]
 
|-
 
|-
−
|[[leather cloak]] || [[cloak]] || 1
 
 
|-
 
|-
−
|[[splint mail]] || [[body armor]] || 1
+
|[[studded leather armor]]
 
|-
 
|-
−
|[[studded leather armor]] || [[body armor]] || 1
 
 
|-
 
|-
−
|[[cloak of displacement]] || [[cloak]] || 2
+
|[[cornuthaum]]
 +
|style="text-align:center" rowspan="1" |[[helm]]
 
|-
 
|-
−
|[[cloak of invisibility]] || [[cloak]] || 2
 
 
|-
 
|-
−
|[[cornuthaum]] || [[helmet]] || 2
+
|[[oilskin cloak]]
 +
|style="text-align:center" rowspan="2" |[[cloak]]
 +
|style="text-align:center" rowspan="6" |2
 
|-
 
|-
−
|[[crystal plate mail]] || [[body armor]] || 2
+
|[[robe]]
 
|-
 
|-
−
|[[dwarvish cloak]] || [[cloak]] || 2
 
 
|-
 
|-
−
|[[orcish cloak]] || [[cloak]] || 2
+
|[[crystal plate mail]]
 +
|style="text-align:center" rowspan="4" |[[body armor]]
 
|-
 
|-
−
|[[plate mail]] || [[body armor]] || 2
+
|[[dwarvish mithril-coat]]
 
|-
 
|-
−
|[[cloak of protection]] || [[cloak]] || 3
 
 
|-
 
|-
−
|[[cloak of magic resistance]] || [[cloak]] || 3
+
|[[elven mithril-coat]]
 
|-
 
|-
−
|[[dwarvish mithril-coat]] || [[body armor]] || 3
 
 
|-
 
|-
−
|[[elven cloak]] || [[cloak]] || 3
+
|[[plate mail]]
 
|-
 
|-
−
|[[elven mithril-coat]] || [[body armor]] || 3
 
 
|-
 
|-
−
|[[oilskin cloak]] || [[cloak]] || 3
+
|[[cloak of protection]]
 +
|style="text-align:center" rowspan="1" |[[cloak]]
 +
|style="text-align:center" rowspan="1" |3
 
|-
 
|-
−
|[[robe]] || [[cloak]] || 3
 
 
|}
 
|}
  
−
Most players like to have maximum magic cancellation, but some favour the benefits conferred by a [[cloak of displacement]] (MC 2).
+
{{upcoming|NetHack 3.7.0|A worn [[amulet of guarding]] adds +2 to magic cancellation.}}
  
−
==Difference between magic cancellation, cancelling a monster, and magic resistance==
+
==Mechanics==
−
Magic cancellation is a property of armor that reduces the probability of certain special monster melee attacks of succeeding. A monster can also be ''cancelled'' by zapping a [[wand of cancellation|wand]] or a [[spellbook of cancellation|spell]] of cancellation. This is somewhat different from magic cancellation. Cancelling a monster completely removes the monsters ability to perform it's special melee attacks, while magic cancellation only reduces the probability of those attacks succeeding against the player. Also, the attacks affected by cancelling a monster are not exactly the same as those prevented though magic cancellation. See the article on [[cancellation]] to compare effects.
+
Magic cancellation protects the player by reducing the ''probability'' of special melee attacks occurring.<!-- Really "occurring"? Or "damaging the player"? -->
 +
* The attack must first hit the player. This means passing the player's [[armor class]]. Unless you are [[resistant]] to the damage type of the attack, you will be dealt damage, which reduces your [[hitpoints]]. This occurs regardless of whether the damage type was ordinary physical, or a special type such as [[poison]].
 +
* After this, there is a probability of special effects occurring, for instance:
 +
** 100% [[Sticking attack|Sticking-to]], [[teleport]], [[sliming]], [[disenchanting]], [[disease]]
 +
** {{frac|3}}  [[Drain level]] and [[paralysis]]
 +
** {{frac|4}}  [[Lycanthropy]], [[slowing attack]], and [[drain energy]]
 +
** {{frac|5}}  [[Sleep]]
 +
** {{frac|8}}  [[Poison]]
 +
* The monster itself must not be [[cancellation|cancelled]]{{refsrc|src/mhitu.c|892|version=NetHack 3.6.0}}.
 +
* Finally, the attack must pass the player's magic cancellation aura. The chance of this happening is 1 &minus; 0.3×MC, or listed in the table below:
  
−
Magic cancellation is not the same as [[magic resistance]]. Magic resistance is an [[extrinsic]] that protects against [[spell]], [[wand]], and [[trap]] effects and damage.
+
{|class="wikitable"
 +
! MC !! Effect probability
 +
|-
 +
| 0 || 100%
 +
|-
 +
|1 || 70%
 +
|-
 +
|2 || 40%
 +
|-
 +
|3 || 10%
 +
|}
 +
 
 +
If all these tests are passed, the player will suffer the special effect. In the case of [[fire]], [[cold]], and [[shock]], there is further a test for determining if any inventory items are damaged or destroyed.
  
−
==How it works==
+
===Cancelable effects===
−
The effects of magic cancellation depend on the ''attack type'' (e.g. bites and breaths) and on the ''damage type'' (e.g. physical or cold). Magic cancellation will only work against ''certain'' attack types that deal a ''certain'' type of damage.  
+
Understanding how magic cancellation works requires some understanding of how an attack works in NetHack. An attack has two characteristics: ''attack type'' (e.g. bites and stings) and ''damage type'' (e.g. physical or poisonous). A [[soldier ant]], for instance, has two attacks: a bite which does 2d4 physical damage (i.e. ordinary damage), and a sting which does 3d4 [[poison]] damage. Magic cancellation will ''not'' protect against the 2d4 physical damage from the bite, ''nor'' will it prevent the 3d4 damage caused by the sting. It will, however, protect against the special effects from the [[poison]]ous sting, which randomly include [[hitpoint]] reduction, [[attribute]] reduction, and [[instadeath]].
  
−
===Damage from the following attack types CAN be affected by magic cancellation ===
+
There is no obvious pattern to what magic cancellation does and doesn't protect against. Shortly put, magic cancellation protects against ''certain'' attack types that deal a ''certain'' type of damage. This relation is shown in the table below. To be prevented by magic cancellation, both the attack type and damage type must be in the <span style="background-color:#ffdead;">orange area</span> of the table. If either the attack type or damage type is outside the orange area, magic cancellation will have ''no effect'' on the attack.
−
Magic cancellation applies only to a certain types of damage delivered through only following types of attacks. Except for the weapon attack, they all involve the monster touching the player with some part of their body:
 
−
* Claw
 
−
* Bite
 
−
* Kick (note that the actual damage done by all kick attacks in the game bypasses magic cancellation)
 
−
* Head butt (note that the actual damage done by all headbutts in the game bypasses magic cancellation)
 
−
* Touch
 
−
* Sting
 
−
* Tentacle attack (note that the actual damage done by all tentacle attacks in the game bypasses magic cancellation)
 
−
* Grabbing attacks (note that the actual damage done by all grabbing attacks in the game bypasses magic cancellation)
 
−
* Weapon attacks
 
  
−
===Damage types that ARE affected by magic cancellation (assuming that the attack type is affected)===
+
In earlier versions of the game, the idea was that some types of armor covered your entire body surface, so the attacker effectively could not touch you despite his successful attack. Over time, with the addition of the [[cornuthaum]] and many types of special attacks, this point has become moot, and the current explanation can only be "it's magic".
−
Assuming that the attack type can be affected by magic cancellation, the following damage types will be affected too:
 
−
* [[Fire]] (e.g. [[fire ant]] bite)
 
−
* [[Cold]] (e.g. [[lich]] touch)
 
−
* [[Shock]] (e.g. [[electric eel]] bite)
 
−
* [[Sleep]] (e.g. [[homunculus]] bite)
 
−
* [[Poison]] (e.g. [[killer bee]] sting)
 
−
* [[Paralysis]] (e.g. [[guardian naga]] bite)
 
−
* [[Drain life]] (e.g. [[barrow wight]] weapon attack)
 
−
* [[Sticky attack]] (e.g. [[large mimic]] bite)
 
−
* [[Lycanthropy]] (e.g. the [[werejackal]] bite when it is in animal form)
 
−
* [[Slowing attack]] (e.g. [[Shade]] touch)
 
−
* [[Teleport]] by the [[quantum mechanic]] claw
 
−
* [[Sliming]] by the [[green slime]] touch
 
−
* [[Disenchanting]] by the [[disenchanter]] claw (note that it does not protect against the [[passive]] disenchanting attack)
 
−
* Constitution draining [[poison]] by the [[rabid rat]] bite
 
−
* Dexterity draining [[poison]] by the [[quasit]] claw
 
−
* [[Power]] draining by the [[energy vortex]] (interestingly, the attack type is ''engulf'', and magic cancellation is hence bypassed. This may be a bug in the source code.)
 
  
−
===Damage from the following attack types is NEVER affected magic cancellation===
+
{|class="wikitable"
−
Regardless of the type of damage, the following attacks types will never be affected by magic cancellation:
+
!colspan="2"|Attack type
−
* [[Passive attacks]]s
+
!colspan="2"|Damage type
−
* [[Spitting attack]]s
+
|-
 +
!style="width:25%"|Attack type unaffected
 +
!width="250px" style="background:#ffdead; width:25%"|Attack type prevented
 +
!width="250px" style="background:#ffdead; width:25%"|Damage type prevented
 +
!style="width:25%"|Damage type unaffected
 +
|-
 +
|valign="top"|
 +
* [[Passive attack]]s
 +
* Spitting attacks
 
* [[Engulfing attack]]s
 
* [[Engulfing attack]]s
 
* [[Breath attack]]s
 
* [[Breath attack]]s
Line 119: Line 171:
 
* [[Gaze attack]]s
 
* [[Gaze attack]]s
 
* [[Magic spell]]s
 
* [[Magic spell]]s
−
 
+
* [[Ranged weapon]] attacks<ref group="note" name="melee_only"/>
−
===Damage types that are NOT affected by magic cancellation===
+
|valign="top" style="background:#ffdead;"|
−
The following monster damage/effects are not affected by magic cancellation, regardless of how the attack was delivered:
+
* Claw
−
* Ordinary physical damage
+
* Bite
−
* [[Magic missile]] damage
+
* Kick<ref group="note" name="never_applies"/>
−
* [[Disintegration]] effects
+
* Head butt<ref group="note" name="never_applies"/>
−
* [[Acid]] damage
+
* Touch
−
* [[Blind]]ing effects
+
* Sting
−
* [[Stun]]ing effects
+
* Tentacle attack<ref group="note" name="never_applies"/>
−
* Leg damage by [[Xan]]s
+
* [[Holding attack]]s<ref group="note" name="never_applies"/>
−
* [[Petrification]] effects
+
* Melee weapon attacks<ref group="note" name="melee_only"/>
−
* [[Gold stealing]] effects by [[leprechaun]]
+
|valign="top" style="background:#ffdead;"|
−
* [[Item stealing]] effects
+
* [[Fire]] (burns scrolls and boils potions)
−
* [[Erosion]] effects (including [[rusting]], [[corroding]] and [[rotting]])
+
* [[Cold]] (shatters potions)
−
* [[Confusion]] effects
+
* [[Shock]] (detonates rings and wands)
−
* [[Digestion]] damage
+
* [[Sleep]] (completely immobilized)
 +
* [[Poison]] (hitpoint and attribute reduction, [[instadeath]])
 +
* [[Paralysis]] (player completely immobilized)
 +
* [[Drain life]] (player loses levels)
 +
* [[Sticky attack]] (inability to move to another square)
 +
* [[Lycanthropy]] (player regularly changes form)
 +
* [[Slowing attack]] (reduces player speed)
 +
* [[Teleport]] (randomly teleports player)
 +
* [[Sliming]] (kills player in a few turns)
 +
* [[Disenchanting]] (reduces enchantment on items)
 +
* [[Dexterity]]- or [[constitution]]-draining [[poison]]
 +
* [[Power]] draining (reduces power)
 +
|valign="top"|
 +
* Ordinary physical
 +
* [[Magic missile]]
 +
* [[Disintegration]]
 +
* [[Acid]]
 +
* [[Blind]]ing
 +
* [[Stun]]ning
 +
* Leg damage by [[xan]]s
 +
* [[Petrification]]
 +
* [[Gold stealing]] effects by [[leprechaun]]s
 +
* [[Item stealing]]
 +
* [[Erosion]] (including rust, rot, and corrosion)
 +
* [[Confusion]]
 +
* [[Digestion]]
 
* [[Healing]] effects by [[nurse]]s
 
* [[Healing]] effects by [[nurse]]s
−
* [[Drowning]] effects
+
* [[Drowning]]
−
* [[Intelligence drain]] effects by [[mind flayer]]
+
* [[Intelligence drain]]
 
* [[Disease]] effect by [[Juiblex]]
 
* [[Disease]] effect by [[Juiblex]]
−
* [[Seduction]] effects
+
* [[Seduction]]
−
* [[Hallucination]] effects
+
* [[Hallucination]]
−
* [[Amulet stealing]] effects by the [[Wizard of Yendor]]
+
* [[Amulet stealing]] by the [[Wizard of Yendor]]
−
* [[Intrinsic-stealing]] effects by [[gremlin]]s
+
* [[Intrinsic-stealing]] by [[gremlin]]s
−
* Random [[clerical spell]] effects, [[magic spell]] effects or [[breath weapon]] effects
+
* Random [[clerical spell]], [[magic spell]] or [[breath weapon]] damage
−
* Special damage effects of the [[Riders]]
+
* Special damage of the [[Riders]]
 +
|-
 +
!Examples &ndash; unaffected due to attack type
 +
!style="background:#ffdead;" colspan="2"|Examples &ndash; prevented due to combination of attack type and damage type
 +
!Examples &ndash; unaffected due to damage type
 +
|-
 +
|valign="top"|
 +
*[[Floating eye]] passive paralysis attack
 +
*[[Disenchanter]] passive disenchanting attack
 +
*[[Guardian naga]] spitting poison
 +
*[[Ice vortex]] engulfing cold
 +
*[[Red dragon]] fire breath
 +
*[[Yellow light]] blinding explosion
 +
*[[Medusa]] petrifying gaze
 +
*[[Pyrolisk]] fire gaze
 +
*[[Lich]] magic spells
 +
|valign="top" style="background:#ffdead;" colspan="2"|
 +
* [[Fire]] damage from a [[fire ant]] bite
 +
* [[Cold]] damage from a [[lich]] touch
 +
* [[Shock]] damage from an [[electric eel]] bite
 +
* [[Sleep]] caused by a [[homunculus]] bite
 +
* [[Poison]] damage from a [[killer bee]] sting
 +
* [[Paralysis]] caused by a [[guardian naga]] bite
 +
* [[Drain life]] by a [[barrow wight]] weapon attack
 +
* [[Sticky attack|Sticking-to]] caused by a [[large mimic]] bite
 +
* [[Lycanthropy]] caused by a [[werejackal]] bite when it is in animal form
 +
* [[Slowing attack|Slowing]] caused by a [[shade]] touch
 +
* [[Teleport]] caused by a [[quantum mechanic]] claw
 +
* [[Sliming]] caused by a [[green slime]] touch
 +
* [[Disenchanting]] by a [[disenchanter]] claw<ref group="note" name="not_passive"/>
 +
* Constitution-draining [[poison]] by a [[rabid rat]] bite
 +
* Dexterity-draining [[poison]] by a [[quasit]] claw
 +
|valign="top"|
 +
*Physical damage due to [[tiger]] claws
 +
*[[Medusa]] petrifying gaze
 +
*[[Raven]] blinding claws
 +
*[[Petrification]] (stoning) due to a [[cockatrice]]'s touch or passive hissing attack
 +
*[[Seduction]] due to [[succubus]] bites
 +
*[[Intelligence drain]] due to [[mind flayer]] tentacle attacks
 +
*[[Purple worm]] engulfing digestion
 +
*[[Drowning]] due to [[giant eel]] wrapping
 +
*[[Hallucination]] caused by a [[black light]] exploding
 +
*[[Erosion]] due to [[brown pudding]] bites
 +
*[[Nymph]] stealing claw
 +
|-
 +
|colspan="4"|
 +
<references group="note">
 +
<ref group="note" name="melee_only">Magic cancellation protects against special melee weapon attacks, such as [[level drain]] from a [[barrow wight]]s weapon, but it does ''not'' protect against weapons that are thrown or launched, such as [[poisoned]] arrows and darts.</ref>
 +
<ref group="note" name="never_applies">The type of damage done by every single kick, headbutt, tentacle attack, and grabbing attacks in the game are listed in the rightmost column "Damage type unaffected". And hence they all bypass magic cancellation.</ref>
 +
<ref group="note" name="not_passive">[[Disenchantment]] by the [[disenchanter]] claw is prevented, but magic cancellation does not however protect against the [[passive]] disenchanting attack, since passive attacks are listed in the leftmost column "Attack type unaffected".</ref>
 +
</references>
 +
|}
 +
 
 +
==Differences from cancellation and magic resistance==
 +
{{main|Cancellation|Magic resistance}}
 +
 
 +
Magic cancellation is distinct from [[cancellation]], which a monster suffers when hit by a [[wand of cancellation|wand]] or [[spellbook of cancellation|spell]] of cancellation. Cancelling a monster completely removes the monster's ability to perform its special melee attacks, while magic cancellation only reduces the probability of those attacks succeeding against the player. Also, the attacks affected by cancelling a monster are not exactly the same as those prevented through magic cancellation. See the article on [[cancellation]] to compare effects.
 +
 
 +
Magic cancellation is not the same as [[magic resistance]]. Magic resistance is an [[extrinsic]] that protects against [[spell]], [[wand]], and [[trap]] effects and damage.
 +
 
 +
Magic cancellation is also different from intrinsic [[resistance]]s against [[fire]], [[cold]], and [[shock]] damage. If you suffer fire damage while [[fire resistant]], you won't be dealt hit point damage, but there is still a chance of items such as [[scroll]]s, [[spellbook]]s, and [[potion]]s being destroyed. Magic cancellation on the other hand won't prevent the damage, but it will reduce the probability of item-destroying effects occurring.
 +
 
 +
==Noteworthy interactions==
 +
* Magic cancellation does ''not'' protect against paralyzing [[passive attacks]] nor [[gaze attack]]s, which include the attacks of [[floating eye]]s and [[Medusa]].
 +
* Magic cancellation ''partially'' protects against [[disenchanter]]s; it prevents the [[disenchantment]] though the claws, but not through the disenchanter's passive attack.
 +
* Magic cancellation does ''not'' protect against the touch nor against the [[cockatrice#Hissing attack|hissing attack]] of the [[cockatrice]]. It is however possible to [[cancellation|cancel]] the cockatrice itself, using a [[wand of cancellation]] or [[spell of cancellation]]. This will remove its ability to petrify by hissing only.
 +
* [[Monster]]s, including [[pet]]s, enjoy magic cancellation from armor just as the player does. This is especially important if you rely on a powerful pet, as monsters cannot gain [[intrinsic]] resistances from [[eat]]ing [[corpse]]s.
 +
{{upcoming|NetHack 3.7.0|Pets can gain intrinsics from eating, though MC is still good for preventing effects that can't be intrinsically resisted.}}
 +
 
 +
==Strategy==
 +
Magic cancellation is a useful properly which gets more useful the more of it you have; a character with MC3 will suffer only {{frac|4}} as many cancellable attacks as one with MC2. However, its value must be weighed against its opportunity costs. Acquiring MC3 requires a cloak of protection, or one of the MC2 cloaks or suits and a source of extrinsic protection. Armor which provides MC2 or 3 doesn't provide the useful properties of the MC1 magic cloaks or MC0 dragon scale mail. In many cases, it's better to wear the cloak of magic resistance to protect yourself from polymorph traps and death magic, or silver dragon scale mail to protect your wands and rings from lightning. Most cancellable attacks have either resistances to negate them, or countermeasures to reverse their effects (fire for sliming, holy water for lycanthropy, Elbereth to unstick from mimics), so a well-prepared player may find magic cancellation a lower priority than more critical properties.
 +
 
 +
Magic cancellation only protects from melee attacks, and characters with strong ranged attacks can generally kill the attackers from a distance before they become a threat. Beware of monsters (especially nasties) being summoned to you, though.
 +
 
 +
If you want MC3, you may want to treat the ring of protection as a situational item, which you equip when a relevant monster appears and then swap out for a more generally useful one when the situation is dealt with. Priests and Samurai get protection from their quest artifacts; other roles must be lawful (at least temporarily) to wish for them.
  
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==Common misconceptions==
+
== History ==
−
* Magic cancellation does 'not' protect against paralyzing [[passive attacks]] nor [[gaze attack]]s, which include the attacks of [[floating eye]]s and [[Medusa]].
+
Before version 3.6.0, magic cancellation was more readily available and stronger, and intrinsic or extrinsic protection had no effect on it. For more details on magic cancellation as it functioned in 3.4.3, see [[Magic cancellation (3.4.3)]].
−
* Magic cancellation partially protects against [[disenchanters]]; it prevents the [[disenchantment]] though the claws, but not through the disenchanters passive attack.
 
−
* Magic cancellation does 'not' protect against the [[cockatrice#Hissing attack|hissing attack]] of the [[cockatrice]].
 
  
 
==References==
 
==References==
 +
<references />
 
* [[Source:Mhitu.c]]
 
* [[Source:Mhitu.c]]
 
* [[Source:Monattk.h]]
 
* [[Source:Monattk.h]]
 +
* [[Source:Monst.c]]
 +
* [[Source:Mthrowu.c]]
  
 +
==External links==
 +
* [http://www.spod-central.org/~psmith/nh/armr-343.txt armr-343.txt]
 +
* [http://alt.org/nethack/topdeaths.html NAO top types of death]
 +
{{nethack-360|offset=1}}
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{{featured}}
 
[[Category:Armor]]
 
[[Category:Armor]]
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{{nethack-343}}
 

Latest revision as of 01:40, 24 March 2024

For the effects of a wand of cancellation or a spell of cancellation, see cancellation.

Magic cancellation, or MC for short, is a graduated property in NetHack which protects the player character from certain non-damaging effects caused by a monster using a contact-making attack.

Description

Magic cancellation offers a certain amount of protection against "special melee attacks" made against a character - examples include poison from killer bee stings, lycanthropy caused by werejackal bites, and the green slime's sliming attacks. Having the highest (best) grade of magic cancellation means that only 1⁄10 of special melee attacks will succeed (assuming they would hit otherwise). This makes magic cancellation a high priority trait. A precise list of the special melee attacks that magic cancellation protects against is provided in the section below.

Magic cancellation must not be confused with cancellation caused by a wand or spell, nor with magic resistance. See § Differences from cancellation and magic resistance for further details.

Your current level of magic cancellation can be verified via any source of enlightenment; "You are warded" means you have MC1, "You are guarded" is MC2, and "You are protected" is MC3.

Sources

The most common source of magic cancellation is armor. Each piece of armor has a magic cancellation number (MC number) ranging from 0 (worst) to 3 (best). Note that magic cancellation from armor is not cumulative—the player's magic cancellation is the maximum of that provided by any single piece of armor worn. This means that if you are wearing a chain mail with MC 1, and a dwarvish cloak with MC 1, then your magic cancellation is still 1.

Magic cancellation can also be granted by protection, either intrinsic or extrinsic. Extrinsic protection augments your magic cancellation by 1, to a maximum of 3. Intrinsic protection or temporary protection from the spell of protection counts as magic cancellation 1, but doesn't stack with armor sources or extrinsic protection. The sources of extrinsic protection are the ring of protection, the Tsurugi of Muramasa, and the Mitre of Holiness; more than one such source provides no additional benefit. Intrinsic protection is granted when you get an AC bonus by donating to an aligned priest or by a favor when praying. Intrinsic protection may be lost by a gremlin's special attack or eating a disenchanter corpse; if so, donating the appropriate amount to an aligned priest will restore it, even if it would fail to improve your AC. High priests have extrinsic protection, and aligned priests and monsters represented by A have intrinsic protection.

The following list contains all the sources of magic cancellation:

Armor Armor type MC
Extrinsic protection N/A +1 (max 3)
Intrinsic protection 1 (if no extrinsic)
spell of protection
alchemy smock cloak 1
cloak of displacement
cloak of invisibility
cloak of magic resistance
dwarvish cloak
elven cloak
leather cloak
mummy wrapping
orcish cloak
banded mail body armor
bronze plate mail
chain mail
leather armor
orcish chain mail
orcish ring mail
ring mail
scale mail
splint mail
studded leather armor
cornuthaum helm
oilskin cloak cloak 2
robe
crystal plate mail body armor
dwarvish mithril-coat
elven mithril-coat
plate mail
cloak of protection cloak 3

The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

A worn amulet of guarding adds +2 to magic cancellation.

Mechanics

Magic cancellation protects the player by reducing the probability of special melee attacks occurring.

MC Effect probability
0 100%
1 70%
2 40%
3 10%

If all these tests are passed, the player will suffer the special effect. In the case of fire, cold, and shock, there is further a test for determining if any inventory items are damaged or destroyed.

Cancelable effects

Understanding how magic cancellation works requires some understanding of how an attack works in NetHack. An attack has two characteristics: attack type (e.g. bites and stings) and damage type (e.g. physical or poisonous). A soldier ant, for instance, has two attacks: a bite which does 2d4 physical damage (i.e. ordinary damage), and a sting which does 3d4 poison damage. Magic cancellation will not protect against the 2d4 physical damage from the bite, nor will it prevent the 3d4 damage caused by the sting. It will, however, protect against the special effects from the poisonous sting, which randomly include hitpoint reduction, attribute reduction, and instadeath.

There is no obvious pattern to what magic cancellation does and doesn't protect against. Shortly put, magic cancellation protects against certain attack types that deal a certain type of damage. This relation is shown in the table below. To be prevented by magic cancellation, both the attack type and damage type must be in the orange area of the table. If either the attack type or damage type is outside the orange area, magic cancellation will have no effect on the attack.

In earlier versions of the game, the idea was that some types of armor covered your entire body surface, so the attacker effectively could not touch you despite his successful attack. Over time, with the addition of the cornuthaum and many types of special attacks, this point has become moot, and the current explanation can only be "it's magic".

Attack type Damage type
Attack type unaffected Attack type prevented Damage type prevented Damage type unaffected
Examples – unaffected due to attack type Examples – prevented due to combination of attack type and damage type Examples – unaffected due to damage type
  1. ↑ 1.0 1.1 Magic cancellation protects against special melee weapon attacks, such as level drain from a barrow wights weapon, but it does not protect against weapons that are thrown or launched, such as poisoned arrows and darts.
  2. ↑ 2.0 2.1 2.2 2.3 The type of damage done by every single kick, headbutt, tentacle attack, and grabbing attacks in the game are listed in the rightmost column "Damage type unaffected". And hence they all bypass magic cancellation.
  3. ↑ Disenchantment by the disenchanter claw is prevented, but magic cancellation does not however protect against the passive disenchanting attack, since passive attacks are listed in the leftmost column "Attack type unaffected".

Differences from cancellation and magic resistance

Main articles: Cancellation and Magic resistance

Magic cancellation is distinct from cancellation, which a monster suffers when hit by a wand or spell of cancellation. Cancelling a monster completely removes the monster's ability to perform its special melee attacks, while magic cancellation only reduces the probability of those attacks succeeding against the player. Also, the attacks affected by cancelling a monster are not exactly the same as those prevented through magic cancellation. See the article on cancellation to compare effects.

Magic cancellation is not the same as magic resistance. Magic resistance is an extrinsic that protects against spell, wand, and trap effects and damage.

Magic cancellation is also different from intrinsic resistances against fire, cold, and shock damage. If you suffer fire damage while fire resistant, you won't be dealt hit point damage, but there is still a chance of items such as scrolls, spellbooks, and potions being destroyed. Magic cancellation on the other hand won't prevent the damage, but it will reduce the probability of item-destroying effects occurring.

Noteworthy interactions

The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

Pets can gain intrinsics from eating, though MC is still good for preventing effects that can't be intrinsically resisted.

Strategy

Magic cancellation is a useful properly which gets more useful the more of it you have; a character with MC3 will suffer only 1⁄4 as many cancellable attacks as one with MC2. However, its value must be weighed against its opportunity costs. Acquiring MC3 requires a cloak of protection, or one of the MC2 cloaks or suits and a source of extrinsic protection. Armor which provides MC2 or 3 doesn't provide the useful properties of the MC1 magic cloaks or MC0 dragon scale mail. In many cases, it's better to wear the cloak of magic resistance to protect yourself from polymorph traps and death magic, or silver dragon scale mail to protect your wands and rings from lightning. Most cancellable attacks have either resistances to negate them, or countermeasures to reverse their effects (fire for sliming, holy water for lycanthropy, Elbereth to unstick from mimics), so a well-prepared player may find magic cancellation a lower priority than more critical properties.

Magic cancellation only protects from melee attacks, and characters with strong ranged attacks can generally kill the attackers from a distance before they become a threat. Beware of monsters (especially nasties) being summoned to you, though.

If you want MC3, you may want to treat the ring of protection as a situational item, which you equip when a relevant monster appears and then swap out for a more generally useful one when the situation is dealt with. Priests and Samurai get protection from their quest artifacts; other roles must be lawful (at least temporarily) to wish for them.

History

Before version 3.6.0, magic cancellation was more readily available and stronger, and intrinsic or extrinsic protection had no effect on it. For more details on magic cancellation as it functioned in 3.4.3, see Magic cancellation (3.4.3).

References

  1. ↑ src/mhitu.c in NetHack 3.6.0, line 892

External links

This page may need to be updated for the current version of NetHack.

It may contain text specific to NetHack 3.6.0. Information on this page may be out of date.

Editors: After reviewing this page and making necessary edits, please change the {{nethack-360}} tag to the current version's tag or {{noversion}} as appropriate.

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